int f(char *s, char *t) 
{ 
 char *p1, *p2; 
 for (p1 = s; *p1; p1++) 
 { 
  for (p2 = t; p2; p2++) 
  { 
   if (*p1 == *p2) 
   { 
    break; 
   } 
  } 
  if (*p2 == '\0') 
   break; 
 }   
 return p1 - s; 
} 
void main() 
{ 
 printf("%d",f("abcd", "babc"));}